The communications industry is rapidly changing to adjust to emerging technologies and ever increasing customer demand. This customer demand for new applications and increased performance of existing applications is driving communications network and system providers to employ networks and systems having greater speed and capacity (e.g., greater bandwidth). In trying to achieve these goals, a common approach taken by many communications providers is to use packet switching technology. Increasingly, public and private communications networks are being built and expanded using various packet technologies, such as Internet Protocol (IP). Note, nothing described or referenced in this document is admitted as prior art to this application unless explicitly so stated.
Real-time packet protocol calls are becoming more and more prevalent over packet networks, such as the Internet, service provider networks, and enterprise networks. For example, these calls may include voice packet protocol calls (e.g., using Voice over Internet Protocol) and/or video packet protocol calls. The device which a person uses in making such a packet call is sometimes referred to as a client call device. These can be, for example, specialized hardware phone available from packet phone and router vendors, or even a personal computer running specialized software to turn the computer into a “soft phone.” These client call devices communicate over a packet network to a call server, such as a Session Initiation Protocol (SIP) call server, which allows calls to be sent to and received from other packet and non-packet client call devices and other endpoints.
Current solutions using real-time packet protocol technology may have many drawbacks. For example, a person may wish to be able to access multiple call servers, which may include private enterprise network (e.g., business) and/or public service provider call servers. This may be especially desirable for traveling and/or telecommuting employees. However, currently, a person will typically use separate and independent client call devices (e.g., one for each call server) or a client call device that allow a selection of various call servers, but only one call server may be selected at a time. Additionally, a personal computer may run separate instances of “soft phone” software which makes the computer seem like multiple client call devices, with each of these independent soft phone client call devices using a different call server. Another common issue is that an enterprise SIP server (e.g., that of a business) is often located behind a network protection device (e.g., firewall, network address translation (NAT) device, network address and port translation (NAPT) device, etc.), which protects the business's corresponding enterprise network. Thus, the client call device of an employee may be blocked from communicating with the enterprise SIP server, and therefore, when off of the business premises, the employee cannot access the enterprise SIP server to send and receive calls and voicemail messages. A client call device may include specialized software which allows it to tunnel into a firewall-protected enterprise network, but this requires specialized software a secure connection established each time the client call device registers with the server. Additionally, this approach requires a separate tunnel for each of the client call devices, which requires a lot of resources, presents many administrative problems, and may present a security point of vulnerability. Desired are better ways of accessing call servers from client call devices.